Greek Mac And Cheese - cooking recipe

Ingredients

3 slices crustless whole wheat bread, torn into small pieces
9 tablespoons unsalted butter, melted
kosher salt, to taste
8 ounces hollow pasta (penne or elbow macaroni)
1/4 cup flour
3 cups milk
4 cups grated graviera cheese (about 12 oz.-you may sub Romano OR Pecorino cheese ) or 4 cups kefalotyri cheese (about 12 oz.-you may sub Romano OR Pecorino cheese )
3/4 teaspoon ground cinnamon
1/8 teaspoon freshly grated nutmeg
fresh ground black pepper, to taste
2 tablespoons extra-virgin olive oil
8 large shallots, finely chopped (or 4 small red onions)
1/4 cup chopped red bell pepper (or orange or green)
16 ounces Baby Spinach, roughly chopped
8 scallions, cut into 1/4-inch thick rounds
1/3 cup roughly chopped fresh dill
1 3/4 cups crumbled feta (about 8 oz.)

Preparation

Put bread into the bowl of a food processor and pulse until finely ground. Put bread crumbs and 3 tablespoons butter into a small bowl and combine; set aside.
Bring a 6 quart pot of salted water to a boil. Add pasta and cook until cooked halfway through, about 3 minutes. Drain pasta, rinse with cold water, and set aside.
Heat the remaining butter in a 4 quart saucepan over medium heat. Add flour and cook, whisking constantly, for 1 minute. Still whisking constantly, slowly drizzle in milk and cook until sauce has thickened and coats the back of a spoon, 10 to 15 minutes. Remove pan from the heat. Stir in cheese, cinnamon, and nutmeg and season with salt and pepper; set bechamel sauce aside.
Heat oven to 350\u00b0. Heat oil in a 5-qt. pot over medium heat. Add shallots and bell peppers and cook, stirring often, until soft, 3 to 4 minutes. Add spinach and scallions and cook, covered, stirring occasionally, until wilted, about 3 minutes. Stir in the reserved bechamel sauce, the dill, and the reserved pasta and move the mixture to a 9\" x 13\" baking dish. Sprinkle evenly with reserved bread crumbs and the feta.
Bake until golden brown and bubbly, about 30 minutes. Let cool for 10 minutes before serving.